The fuse is a kind of electrical appliance for security protection, it can be used for isolated protection between power source and loads, is also widely used as a protector for power grid or electrical equipment, namely, fuse appliance is capable of automatically switching circuits off in case of short-circuit or overload in power grid or line of electrical equipment, in order to avoid damage to electrical appliances and equipment and prevent the spread of the accident. The basic structure of a fuse appliance consists mainly of three parts, including a fuse, a fuse carrier and a fuse appliance base. The fuse plays such a role that it will get overheated and melts when excessive current is caused by circuits overload or short-circuit failure, thereby putting electrical equipment under protection. The fuse carrier and the fuse appliance base are used for support, insulation and protection and are made of insulating materials. A cavity for receiving the fuse is arranged on the fuse carrier, moving contacts of the fuse appliance are arranged on the two sides of the cavity, the fuse carrier is generally manufactured to be manually operable, so as to remove or insert the fuse when the fuse is replaced by an operator. Fixed contacts that can come into contact with the moving contacts arranged on the fuse carrier and wiring terminals are arranged on the fuse appliance base, and the fuse appliance base is used not only for mounting and fixing the fuse, but also for realizing an electrical connection between the fuse and the circuit. During the use of the fuse appliance, fuse replacement is often needed, namely removing the old or blown fuse and inserting a new fuse, and this operation is a charged operation, therefore, convenience and easiness are required in the fuse replacement operation, furthermore, operator's safety must be guaranteed.
Fuse appliances in the prior art can be classified in two types based upon their fuse replacement ways, i.e. straight pull type and rotational type. The straight pull type fuse appliance is characterized in that, when the fuse is replaced or mounted, the fuse carrier for carrying the fuse in the fuse appliance base is directly pulled out of the base to isolate the fuse from the contacts, such a structure has the advantage of large isolation distance between the fuse and the contacts to further result in good safety, however, the operation is laborious and inconvenient. The rotational type fuse appliance is characterized in that, when the fuse is replaced or mounted, the fuse carrier is rotated about a fixed fulcrum of the base by a particular angle in order to isolate the fuse from the contacts, such a structure has the advantage of labor-saving operation, but there is a small isolation distance between the fuse and the contacts, which means poor safety. However, in order to solve the aforementioned shortcomings in the prior art, innovation needs to be put on an operation mechanism of the fuse carrier in relation to the fuse appliance base, and with this novel operation mechanism, such use requirements as small operation force, convenient fuse replacement and good operation safety can be met, in addition, optimization on the structure and functionalities of the fuse appliance can also be implemented.